Solid-fuel propulsion device

The solid propellant (12) has a burning chamber (16) withy one partition (26a) and another partition (26b) that are separated from each other by a partition wall (24). Former partition has a propellant (28a), which is arranged to be ignited in latter partition independent from another propellant (28b). The partition wall has a plate stretching in longitudinal direction (L). The plate is connected at edges with an outer wall (20) of the burning chamber, so that the partitions are formed in wedge-shape or cylindrical segment shape. Independent claims are included for the following: (1) a method for operating a solid propellant; and (2) a missile.